Th17 cells belong to a unique group of CD4+ T cells, and are considered as T cells which are able to produce IL-17A and IL-17F (Harrington et al., 2005; Park et al., 2005; Langrish et al., 2005). Differentiating from Th1 and Th2 cells, development of Th17 cells are regulated by TGF-β and other inflammatory cytokines, such as IL-6, IL-21, IL-1β and IL-23 (Bi and Yang, 2012). In addition to IL-17A and IL-17F, Th17 cells also can secrete other indicator cytokines, such as IL-21, IL-22, IFN-γ, IL-4, IL-10, IL-9, IL-26, CXCL8 and CCL20, etc. (Marwaha et al., 2012), and thus they can affect other cells, such as fibroblasts, keratinocytes, endothelial cells, neutrophils and memory T cells, etc. (Gaffen, 2011; Ghoreschi et al., 2011; Wilke et al., 2011). At present, it has been found that Th17 cells and the acting factors thereof, such as IL-17, IL-21, IL-22, GM-CSF and CCL20, etc. are related to pathogenesis of autoimmune diseases and inflammatory diseases, such as systemic lupus erythematosus (SLE), psoriasis, rheumatoid arthritis (RA), multiple sclerosis (MS), inflammatory bowel disease, allergy, asthma, etc. (Maddur et al., 2012).
Antrodia cinnamomea (also named Antrodia camphorata or Taiwanofungus camphoratus) is a traditional Chinese herb, which is a fungus endemic to Taiwan and only parasitizes in solid wood or on the moist surface of Cinnamomum kanehirae Hayata (Lauraceae) (Ao et al., 2009; Lu et al., 2009). At present, Antrodia cinnamomea has been applied to the treatment of hepatitis, cancers, abdominal pain, diarrhoea, hypertension, and used for liver protection, detoxification, etc. However, it is still not clear whether Antrodia cinnamomea has the effect of modulating Th17 cells or not.